Last week, Twitter’s spam filters broke Twisst, the clever tool that sends you a tweet when the International Space Station (ISS) will be visible at whatever location you have in your Twitter bio. After an outcry from Twisst users, Twitter contacted Twisst and the two started talking about what could be done.

On its blog, Twisst explains what went down. One of the ways Twitter is fighting spam is by limiting how many tweets you can send per account, per day, and per hour. Here are the current cutoffs, according to the About Twitter Limits webpage:

Direct messages: 250 per day.

Tweets: 1,000 per day. The daily update limit is further broken down into smaller limits for semi-hourly intervals. Retweets are counted as Tweets.

Changes to account email: Four per hour.

Following (daily): The technical follow limit is 1,000 per day. Please note that this is a technical account limit only, and there are additional rules prohibiting aggressive following behavior. Details about following limits and prohibited behavior are on the Follow Limits and Best Practices page.

Following (account-based): Once an account is following 2,000 other users, additional follow attempts are limited by account-specific ratios. The Follow Limits and Best Practices page has more information.

Twisst requires many accounts to send space station alerts to all its 48,000+ followers. Jaap Meijers, the man behind Twisst, says he has put a lot of effort into getting better at avoiding the limits and fine-tuning accounts to have them look less like spam accounts.

When Twitter started blocking Twisst’s sender accounts though, Meijers thought it was because of another limit (the number of tweets coming from one IP address). He looked at various ways around this, but all the solutions pointed to creating even more accounts (more than 2,200, by his estimate). Thankfully, Twitter stepped in to fix the problem:

Twitter contacted me and unsuspended all blocked sender accounts (about 200!). They promise to unsuspend them again the next time their automated spam algorithms put them out of order.
They also propose sending a portion of the alerts as DM’s. I will start looking into changing my system to do that. If you have no problem with getting your alerts as DM, then this could be a way to keep Twisst up and running.

In addition, Meijers is already looking at his options to avoid being marked as spam. He plans to create filters so you won’t get alerts for “passes you don’t want to know about anyway, like maybe early morning passes.” Not only will this improve the service, but as a result Twisst will send out fewer tweets, decreasing the chances it will get banned by Twitter. Here’s Meijers’ projection:

For now though, I think he’s just happy Twisst is operational again. So are we.